Anchoring device for well tools



Ap 1964 c. B. COCHRAN ETAL 3,130,783

ANCHORING DEVICE FOR WELL. TOOLS Filed March 27, 1962 3 Sheets-Sheet 1 zCHUDLE/GHB. CD /{MN L/A MES D. MO T 7' INVEN TOR.

A rrM-A/FY April 28, 19 c. B. COCHRAN ETAL 3,130,738

ANCHORING DEVICE FOR WELL. TOOLS Filed March 27, 1962 3 Sheets-Sheet 2 ATTOR/VEY April 28, 1964 c. a. COCHRAN ETAL 3,130,788

ANCHORING DEVICE FOR WELL TOOLS 5 Sheets-Sheet 3 Filed March 27, 1962CHUDLf/Q/ B. COCA r64 JAMES D. MOTT ATTOR/VE Y Jnited States Patent3,130,788 ANCHORING DEVICE FOR WELL TOOLS udleigh B. Cochran and JamesD. Mott, Houston, Tex.,

assignors to Cicero C. Brown, Houston, Tex. Filed Mar. 27, 1962, Ser.No. 182,886 13 Claims. (Cl. 166-217) this invention relates toimprovements in anchoring ices for well tools and refers moreparticularly to h anchoring devices especially adapted for securing'ious well tools within a string of well pipe at preected levels thereinand in such manner that the tools .y be released and withdrawn from thewell pipe when tired. anchoring and landing devices currently in useinde as basic elements a locator tool and a latching color landingnipple placed in the pipe string to establish )lace to land an anchoringdevice. This requires a of latch elements variously called dogs orslips, on anchoring device with a configuration which will corpond tothe configuration of grooves or recesses med in the landing nipple. Whenthe locator tool is 1. into a well pipe, such as a tubing string, on awire a, the tool will pass all collar recesses and other inruptions inthe smooth bore of the tubing string, but en the tool comes to a recessin a landing nipple hava configuration matching that of the latchelements, locator will project into that recess and anchor the l at thispoint. Frequently several such tools must be ded in a tubing string andin order to accomplish this, i of matching configurations for the latchelements I landing nipple recesses are required to selectively the toolsin their proper positions. It will be seen, refore, that each landingnipple must have a configura- 1 peculiar to latches on the particulartool to be landtherein. Accordingly, it will be evident that it is'antageous both economically and to simplify operais to have theengaging parts of all tools and landing ples of the same configuration.another disadvantage of the present landing nipple tions is that theyrequire locking grooves or recesses ing upwardly facing abrupt stopshoulders. Such iulders contribute to difficulty in running other wire 2devices through the nipple sections. Fhe present invention has for itsprimary object the vision of an anchoring device employing a single setlatch elements and landing nipples having recesses of form configurationcorresponding to the single set of :h elements. This arrangementprovides a simple econical and compact structure. t is, therefore, animportant object of this invention to wide an anchoring device of simpleand compact coniction that may be selectively set in any one of a pluityof like landing nipples in a pipe string. \nother important object is toprovide a simple, posimeans of attaching the anchoring device to thewire a by which it is run into the hole and which will rese the wireline from the anchoring device automatily when the tool is anchored. )neobject of this invention is to provide an anchordevice that may beanchored in a landing section hout the necessity of an abrupt stopshoulder thus ninating a place which wire line tools would have difiltyin passing. 8 very important object of this invention is to proe ananchoring device with a pressure balanced actuatand releasing mandrelsuch that difierential pressure ing from either above or below the toolwill not unset anchoring device. still further object of this tool is toprovide a means bleeding oil pressure below the tool while it is seelylocked in its anchored position to obviate the ice possibility ofprematurely releasing the tool before the pressure is bled OE and havingthe device blown up the hole.

Additional objects and advantages of the invention will be readilyapparent from the following detailed description of a device constructedin accordance with one embodiment of this invention, reference being hadto the accompanying drawing thereof, wherein:

FIG. 1 is a view, partly in elevation and partly in section, of thelocking and scaling portion of a landing section and showing ananchoring device being lowered into the tubing past the anchoringposition;

FIG. 2 is a view similar to FIG. 1, showing the anchoring device inposition in the landing section as the anchoring device is being raised;

FIG. 3 is another view similar to FIGS. 1 and 2, showing the anchoringdevice raised above its anchoring position preparatory to lowering andseating it in anchored position;

FIG. 4 is a view similar to FIGS. 1, 2 and 3, showing the anchoringdevice anchored into position in the landing section and also showingthe wire line running tool released and withdrawn;

FIG. 5 is a horizontal cross-sectional view taken on the line 5-5 ofFIG. 3;

FIG. 6 is a horizontal cross-sectional view taken on line 6-6 of FIG. 3;

FIG. 7 is a horizontal cross-sectional view taken on line 7-7 of FIG. 4;

FIG. 8 is a horizontal cross-sectional view taken on line 88 of FIG. 1;

FIG. 9 is a horizontal cross-sectional view taken on the line 9--? ofFIG. 1; and

FIG. 10 is a fragmentary view of a modification of the anchoring device.

In the drawings (FIGS. 1 to 4), there is shown a portion of a pipestring P which may be a string of flow tubing for conducting well fluidsfrom a producing formation of a well to the ground surface. Pipe stringP is made up of a plurality of lengths of tubing 10 between sections ofwhich are interposed one or more latching collars or landing nipples 11having a bore 12 which is substantially flush with bore Illa of tubing10. Each landing nipple has an internally threaded socket 13 at itsupper end for connection to the threaded pin 14 on a section of thetubing, and has an externally threaded pin 15 at its lower end forreception in the box portion 16 of the next adjacent section of tubing10. It will be understood that as many of these landing nipples may beinstalled in a tubing string as may be found necessary for anchoring avariety of tools. It will be understood that these landing nipples areidentical in construction and the description of one will, of course, beapplicable to all others which may be incorporated in the tubing string.

An annular positioning and locking groove 17 is provided in the borewall of nipple 11 and has its upper and lower ends formed as inclined,inwardly converging upper and lower shoulders 18 and 19, respectively.

The anchoring device, for use with the landing nipples, comprises ananchoring section, designated generally by the numeral 2%), and alanding and retrieving section, designated generally by the numeral 21.Anchoring section 20 includes a tubular body 22 having an axial bore 23counterbored from its upper end to form the counterbore 24 and definingthe upwardly facing internal shoulder 25. The exterior of body 22, froma point just below shoulder 25, is reduced in diameter at 26 to definethe downwardly facing annular shoulder 27. The lower end of reduceddiameter surface portion 26 is externally threaded at 28. A tubular slipcage 29 having an internally threaded socket 30 threadeclly receives thelower end of body 22. The upper end of cage 29 forms an externalshoulder 31 which is spaced from shoulder 27 defining therebetween apacking recess in which is mounted a plurality of rings of aconventional packing 32. A plurality of radial windows 34 (three shown)are cut through the wall of slip cage 29 on 120 spacing and are ofgenerally rectangular configuration adapted to receive therein slips 35which are radially movable in the windows. Cage 29 has an internal bore36 which is larger in diameter than bore 23 of the body. The portion ofbore 36, a short distance below windows 34, is reduced in diameter at 37and this reduced diameter portion is undercut to form the recess 38defining the downwardly facing internal shoulder 39. The exterior of thelower end of cage 29 is reduced in diameter and externally threaded toreceive a cap 40 having an axial bore 42 substantially flush with thebore of reduced diameter portion 37 and when screwed into place on thelower end of cage 2) defines the lower wall of recess 38. The lower endof body 22 is bevelled to define the downwardly tapering shoulder 43 andthe reduction in bore diameter at 37 relative to bore 36 provides anoppositely bevelled shoulder 44, shoulders 43 and 44 being spacedapproximately equal distances above and below windows 34.

Slidably disposed in the bore of body 22 is a generally cylindricalmandrel, designated generally by the numeral 45, comprising co-axiallyconnected upper and lower Sections 46 and 47, respectively, having acommon bore 48 which opens to its lower end. The lower end of themandrel projects below the lower end of anchoring section 20 and will beprovided with suitable means (not shown) for connecting thereto any typeof tool which it is desired to anchor in the pipe string. However, it isa feature of this invention that the anchoring device may be used simplyas a plug for the tubing, in which case no other tool need be attachedto the mandrel. The upper end of mandrel portion 46 is internallythreaded to receive a closure plug 51 which is screwed into the upperend of mandrel portion 46. Plug 51 serves to close off bore 48completely against fluid flow from the upper end of mandrel portion 46.Plug member 51 has a radially enlarged section 52 which extends radiallyoutwardly of the exterior of mandrel portion 46 and defines a downwardlyfacing shoulder 53. Plug member 51 is provided with an upstandingtubular extension 54 having an external diameter less than that ofenlargement 52, the bore of extension 54 defining the socket 54a. Plugmember 51 forms a part of the means by which the anchor member 26 isconnected to landing and retrieving section 21 and will be described ingreater detail hereinafter.

The lower end of upper mandrel portion 46 is internally threaded to forma box 55 to threadedly receive the upper end of lower mandrel portion47. The exterior wall of box 55 is dimensioned to form a close slidingfit in bore 24 of body 22 and a slidable seal 56, such as a conventionalO-ring, is mounted in the exterior of box 55 to seal with the wall ofbore 24. The exterior of upper mandrel portion 46 just above box 55 isreduced in diameter to provide the upwardly facing shoulder 57 and todefine an annular space 58a between the exterior of mandrel portion 46and the wall of counterbore 24. A tubular bushing 58 is screwed into theupper end of body 22 and has a bore providing a sliding fit about theexterior of mandrel portion 46 and forming a closure for the upper endof annular space 580. A sleeve piston 60 is slidably mounted in theupper portion of annular space 58a and is provided with internal andexternal seals 61 and 62, respectively, to form a sliding seal betweenthe exterior of mandrel portion 46 and the wall of counterbore 24. Acoil spring 63 is mounted about mandrel portion 46 in space 58a and hasa free length less than that between shoulder 57 and the lower end ofpiston 60, but which, at certain stages of operation of the device, aswill appear hereinafter, will be compressed therebctwecn to urge thesemembers apart. The upper end 64 of piston 60 and the opposing end face65 of bushing 58 are oppositely bevelled to form inwardly convergingearn surfaces between which are mounted a plurality 01 ball detents 66which are urged outwardly toward the exterior of mandrel portion 46 bycooperation of the carr surfaces under pressure exerted against piston60. The exterior of mandrel portion 46 is provided with an annularlatching groove 67 into which detents 66 will project when the mandrelis moved to a position at whicl'. groove 67 is in registration withdetents 66. One or more radial ports 68 are provided through the wall ofbody 22 at a point just below bushing 58 and provides fluidcommunication between the portion of annular space 5811 occupied bydetents 66 and the exterior of body 22. One or more radial ports 69 areprovided through the Wall 01 mandrel portion 46 above shoulder 57 toprovide communication between bore 45 of the mandrel and annular space580. One or more radial ports 70 are provider through the wall of body22 at a point immediately above internal shoulder 25 to providecommunication betweer the portion of annular space 58a which is belowbox 55 and the exterior of body 22. When there is a ditferentiaipressure from below the anchoring device, pressure ma} enter ports 69from bore 48 and act against piston 60 Thus the pressure will act tomove the cam surfaces 64 and 65 together which will force the balldetents 66 inwardly toward the exterior of the mandrel. Once the balidetents latch into the groove 67 any differential pressurr from belowthe tool would act against the piston and prevent the balls from comingout of the groove. This effec' tively holds the mandrel in the setposition (FIG. 4) S( that it cannot be moved to release the slips ordogs 35 until the pressure above and below the tool is equalized Apacking ring 71, such as a conventional O-ring, i: mounted in the wallof bore 23 between shoulder 25 ant the lower end of the body to form aslidable seal be tween the body and the exterior of lower mandrel portion 47. The lower end portion of lower mandrel por tion 47, whichprojects through cap 40, is provided witl an elongate annular groove 72defined by an upper shoul der 73 and a lower shoulder 73a. This annulargroovi 72 is movable longitudinally in response to the move ments of themandrel between a position at which groovs 72 is in registration withrecess 38 and at which upper shoulder 73 is below recess 38. A split orsegmentec retainer ring 74 is mounted in recess 38 and is confinet by agarter spring 75 to urge the segments about the ex terior of the mandrelso that when groove 72 is oppositr recess 38, retainer ring 74 willcollapse inwardly ant enter groove 72 (FIG. 2) and lock the mandrelagains downward movement by engagement with shoulder 73 Returning now tothe locking slips 35. These are gen erally rectangular in outline to befreely slidable in win dows 34 and are generally arcuate in transversecros: section having a smooth convex exterior surface 41 ant providedwith lateral extensions 35a which project intc an annular recess 36a inthe wall of bore 36 (FIGS. 1 and 8) to prevent the slips from fallingoutwardly frorr windows 34. The inner face of each slip is defined by 2pair of longitudinally spaced outwardly projecting ar cuate shoulders 76and 77 at its upper and lower ends the opposed inner faces 78 and 79,respectively, 01 shoulders 76 and 77 forming the opposite end walls 01an intervening groove 89. End faces 78 and 79 art bevelled to convergeinwardly toward the bottom 0: groove 80. The outer faces 81 and 82,respectively 0: shoulders 76 and 77 are bevelled downwardly and inwardlyfrom the adjacent ends of the slip toward the inner face of the slip.Outer edges 83 and 84 of th: ends, respectively, of each slip arebevelled outwardly toward the outer face of the slip, being inclinedoppo sitely to faces 81 and 82. The angles at which the sev eral facesare bevelled are preferably uniform and desir ably in the range of fromabout 40 to about 50.

Mandrel portion 47 is provided at a point a short dis :e above groove 72with a pair of external longitudily spaced upper and lower circularshoulders or lugs and 91, respectively, of substantially the samegestric shape in longitudinal cross-section as shoulders and 77 on theslips, having cylindrical outer end faces bevelled upper and lower faces92 and 93, respecly, on shoulder 90 and upper and lower faces 94 andrespectively, on shoulder 91. Shoulders 90 and 91 ne between them anannular recess 96 having subltially the same length as recesses 80 inthe slips.

"he dimensions and relative positions of shoulders 90 91 and shoulders76 and 77 on slips 35 are such that respective shoulders may movelongitudinally relato each other in response to relative movement beenthe mandrel and the slips between positions at ch shoulders 90 and 91are in direct registration with ulders 76 and 77 (FIGS. 2 and 4), tothereby radially ject slips 35, and positions providing a relationship:rein shoulders 90 and 91 are interspersed with ulders 76 and 77 tothereby permit inward collapse slips 35 (FIG. 1). In the interspersedrelationship, ulders 90 and 91 may move between positions above G. 3)and below (FIG. 1) the respective shoulders and 77, as will appearsubseqeuntly in the descript of the operation of the device.

.anding and retrieving section 21 includes a tubular ve 100 having abore 101 opening to its lower end, bore having a diameter such as toslidably receive tally enlarged section 52 of mandrel plug 51. The erend of sleeve 100 is internally threaded to receive tbular bushing 103having a bore dimensioned to slid- I receive the upper end portion ofmandrel section 46. :oil spring 105 is positioned about the upper end ofidrel section 46 in compression between shoulder 53 the inner end ofbushing 103, thereby normally biasmandrel 45 upwardly relative to sleeve100 and anring section 20. A pair of seal rings l06106 are lnted in thebore wall of bushing 103 to form spaced able seals between bushing 103and the exterior of idrel section 46. Adjacent its lower end, the wallof hing 103 is provided with radial ports 107 providing tmunicationbetween the interior and exterior of the hing. Mandrel section 46 isprovided with a radial port providing communication between mandrel bore48 the exterior of the mandrel and which is adapted ve positioned inregistration with ports 107 at certain tive positions of the mandrel andout of registration l ports 107 at other relative positions of themandrel, will appear hereinafter. The upper end portion of ve 100 isreduced in external diameter to form a fishneck 110 having a radialflange 111 at its upper end adapted to be grasped by a conventionalovershot aimilar fishing tool. Fishing neck 110 has an axial 110:: whichis substantially flush with the wall of :et 540. An internal annularshoulder 112 is formed ore 101 of sleeve 100 at a point near its upperend the inner wall of shoulder 112 is provided with a low annular groove113. A plurality of ball detents are circumferentially disposed inball-holding pockets extending through the wall of socket 54. The innerof pockets 116 are dimensioned to permit only a ion of detents 115 toproject into socket 54a and the neters of detents 115 are made greaterthan the thickof the wall of socket 54a so that a portion of the ntswill also project outwardly of the ball pockets be engaged in groove 113when the latter is in regison with the detents, as best seen in FIGS. 1,2 and 3. or more shear pins 117 extend through the wall of ve 100 intoenlargement 52 to thereby lock these s together in the positions shownin FIGS. 1, 2 and 3. parts are re-releasable for relative movement by.king of the shear pins, as will appear subsequently. running tool T,which is adapted to be run on a wire tool string or the like, has acylindrical shank 120 ing an external diameter such as to slide freelythrough bore a and into socket 54a. A downwardly facing shoulder 121 isprovided at the juncture of shank 120 to tool T which is adapted toengage the upper end of flange 111, thereby limiting downward movementof tool T into sleeve 100. Adjacent its lower end, shank 120 is providedwith a shallow annular recess 122, the upper and lower ends of which aredefined by bevelled shoulders 123 and 124. The depth of recess 122 andof groove 113 are dimensioned relative to the diameter of detents sothat when groove 113 is in registration with detents 115, the latterwill project into recess 122 and groove 113. Any tendency to upwardmovement of shank relative to socket 54a and sleeve 100 will dispose theinclined shoulder 124 against the projecting portion of detents 115, asseen in FIG. 2, urging the detents outwardly of pockets 116 and intogroove 113. The depth of the latter is made such that detents 115 cannotmove outwardly far enough to allow shoulder 124 to pass the detents 115and thus release shank 120. As a result, detents 115 cooperate with theshank to effectively connect the device to the running too]. Relativedownward movement of shank 120 will allow detents 115 to move intorecess 122, a distance suflicient to allow shoulder 112 in sleeve 100 toclear the detents and move below the same, in which position detents 115will be free to fall outwardly into the upper portion of bore 101 aboveshoulder 112, as best seen in FIG. 4, bore 101 thereby releasing thedetents from their engagement with shank 120 and permitting the runningtool to be withdrawn from the anchoring structure, as will appear morefully hereinafter.

Operation of the device is as follows: In FIG. 1, the structure is shownwith the parts in the relative positions occupied when running the toolinto pipe string 10. Running tool T will be secured in socket 54a and asthe device is run into the well the friction of packing 32 against thewall of the landing nipples and fluid drag will cause shoulder 121 tobear against the upper end of flange 111, thereby pushing the anchoringdevice downwardly through the bore of the pipe string. It will be seenthat shoulders 90 and 91 are interspersed with shoulders 76 and 77,being disposed, respectively, beneath the latter. Ports 108 and 107 willbe in registration so that any fluid in the pipe string will bedisplaced through the bore of the mandrel by the downward movement ofthe tool and can flow out of the interior of the mandrel into the boreof the pipe string. As seen in FIG. 1, the tool is shown in a positionat which slips 35 are passing below one of the locking grooves 17 in alanding nipple 11. As seen, slips 35 are in the collapsed position andthus may freely pass through the bore of the tubing and the landingnipples, and thus may be moved past any number of such landing nipplesand their respective locking grooves until the tool has attained aposition below the particular locking groove at which it is to beanchored. Thereupon, an upward pull is taken on the string. As the slipscome to a position directly opposite the groove 17, as shown in FIG. 2,the slips will be free to move outwardly into the groove and thefriction between packing 32 and the wall of the landing nipple willpermit an amount of upward movement of mandrel 45 relative to slip cage29, allowing shoulders 90 and 91 to move upwardly past respectiveshoulders 76 and 77 on the slips, as shown in FIG. 2, to the positionillustrated in FIG. 3, at which shoulders 90 and 91 will be above andresting on the respective shoulders 76 and 77. At the same time, theupward movement of the mandrel will move groove 72 upwardly inregistration with retainer ring 74, permitting the latter to becollapsed by garter spring 75 into groove 72 limiting longitudinaltravel of the mandrel to the distance between shoulders 73 and 73a.Spring 63 will be compressed tending to urge mandrel 45 and anchoringsection 20 apart, and thus provide a so-called cocking force tending tomove shoulders 90 and 91 back toward their former positions belowshoulders 76 and 77.

The tool string will now again be lowered, with packing 32 providingfriction drag against the wall of landing nipple 11 and resistingmovement of body 22 through the nipple, until slips 35 are againopposite groove 17 at which point the slips, being free to move intogroove 17, will allow shoulders 90 and 91 on the mandrel to movedownwardly under the force of spring 63 and the weight of the toolstring until shoulders 90 and 91 are in registration with shoulders 76and 77, as shown in FIG. 4. The downward movement of the mandrel islimited by the engagement of shoulder 73 with the upper end of retainerring 74 to thereby hold shoulders 90 and 91 in the position registeringwith shoulders 76 and 77 and the tool will thereby be anchored in groove17. At the same time, latching groove 67 will be moved to a position inregistration with detents 66 and the latter will project into groove 67under the pressure of spring 63 and thereby lock the mandrel againstupward movement relative to the anchoring section and complete thelatching of the tool in the landing nipple. Detents 66 become efiectivefor holding the mandrel against upward movement by reason of thebalancing pressures provided by ports 69, which thus permits the samepressure to be exerted both against the mandrel and against the detentsthrough the sliding piston 60.

When the tool has reached the landing position, as just described, ajarring blow will be struck downwardly on the running string sufficientto break shear pin 117 and thereby permit sleeve 100 to move downwardlyuntil the lower end of the sleeve is in abutting engagement with theupper end of cap 58, as best seen in FIG. 4. This movement of sleeve 100will move seal rings 106-106 to a position sealing off ports 108 fromports 107 and thus effectively seal off the bore of the mandrel from theinterior of tubing T and complete the setting of the tool. With shearpin 117 broken, spring 105 will act to keep sleeve 100 in its downwardposition, keeping ports 108 isolated by seals 106-106.

When sleeve 100 has moved to the position shown in FIG. 4, detents 115will be released for movement outwardly into the upper portion of bore101, thereby freeing shank 120 of the running tool and allowing thelatter to be drawn upwardly out of socket 54a, thereby permitting therunning string to be withdrawn from the well, as illustrated in FIG. 4.

When the tool is in the set position (see FIG. 4) a higher differentialpressure from below the tool will act upward on the cross-sectional areaof the mandrel defined by seal 71. This force would tend to move themandrel upward which would unset the tool. To counteract this force thepressure enters ports 69 and then acts downward on the shoulder 57 whichhas the same area as the cross-section defined by seal 71. Therefore,the mandrel is pressure balanced and the resultant force on the mandrelis zero.

When it is desired to remove the anchoring device from the landingnipple, a tool string will be run back into the well carrying a suitableand generally conventional overshot for grasping flange 111 of fishingneck 110. Upward pull on the tool string will then raise sleeve 100 backto a position which will again uncover ports 108, permitting bleed-offof pressure through ports 108 and 107 to thereby permit the tool to bereleased. The latch formed by detents 66 and groove 67 will hold mandrel45 stationary while sleeve 100 is thus being pulled upwardly to effectthe described pressure release. When pressure has thus been bled-off,continued upward pull applied to flange 111 of the fishing neck willpull mandrel 45 upwardly, moving shoulders 90 and 91 upwardly to theposition shown in FIG. 3, thereby permitting the slips 35 to collapseinwardly and freeing them from groove 17. As upward pull is continued tobe applied to the mandrel, shoulder 90 will engage beneath shoulder 43,thereby securing the mandrel to the anchoring section and permitting theentire anchoring tool to be withdrawn from the landing nipple and thencethrough the tubing string to the surface.

It will be seen that when sleeve member has been moved to its lowermostposition, as shown in FIG. 4, the anchoring device may serve as a plugfor the tubing string, since all communication between the interior olthe mandrel and the exterior of the tool has been sealed off above theprincipal seal provided by packing 32.

FIG. 10 illustrates a modification of the anchoring structure inaccordance with this invention, which is designed for use in a tubingstring which has been installed without the use of specially groovedlanding nipples. This embodiment provides a structural form whichenables the anchoring device to be anchored in the collar recessesformed at the joints defined between the ends of adjoining sections ofthe tubing string which are threadedly connected together by means ofconventional threadec' collars.

As illustrated in FIG. 10, two sections 10a and 10b 01 the tubing stringare shown connected by a conventional threaded collar C. The ends of theadjoining tubing sections are spaced apart in the normal manner by thespace 17a which, for the purposes of this invention, functions in thesame manner as groove 17 of a landing nipple.

The details of the anchoring device employed for use in thismodification are identical with those of the previously describedembodiments, with the exception of the external shape of slips 35. Inthe modification illustrated in FIG. 10, slips 35 are identical withslips 35 ir their internal construction in having shoulders 76' am 77substantially identical in form and arrangement witl' shoulders 76 and77 of the previously described embodiment. However, the exterior surfaceof each of the slip: 35 is provided at a medial point thereon with atransverse external shoulder 41 which is trapezoidal in longitudinasection defined by the converging upper and lower edge: 83' and 84'.Shoulders 41' have a length such as to be slightly less than the lengthof recess 17a, so that the will project into the latter and engage theends of the connected tubing sections 10a and 10b for securing th:anchoring device in the recess in response to the sam: manipulativemovements employed in activating the pre viously described embodimnet.

From the foregoing, it will be seen that the dcvict heretofore describedprovides a structure adapted to ful fill the various objects andadvantages which have beer previously noted. It will be evident that incases when the device is to function solely as an anchor, seal pack ing32 may be dispensed with, if no scaling function it required.

It will be understood that numerous changes and modi fications may bemade in the details of the illustrative embodiment within the scope ofthe appended claim: without departing from the spirit of this invention.

What we claim and desire to secure by Letters Paten is:

1. For use in pipe strings having longitudinally spacer annular recessesin the wall thereof, an anchoring devic: anchorable in a selected one ofsaid recesses, comprising a tubular body insertable in the bore of apipe string openings in the Wall of said body, latch members mount ed insaid openings for radial movement into and out 0: said recesses, saidlatch members having inwardly pro jecting shoulder means, a mandreldisposed in the bore 0' said body for longitudinal movement relativethereto radial enlargements on the mandrel movable with lht mandrelrelative to the latch members between position: in and out ofregistration with said shoulder means whereby respectively to radiallyproject said latch mem bers into said recesses and to release said latchmember: for retraction from said recesses, cooperating stop mean:carried by the body and the mandrel limiting the rela tive movement ofthe mandrel to attainment of said po sitions, cooperating releasablelatch elements positioner on the body and mandrel to releasably securesajd man drel to the body when said shoulder means is in registra tionwith the shoulder means on said latch members, am

mm for applying upward pull on said mandrel to retse said latch elementsand to move said enlargements t of registration with the shoulder meanson said latch :mbers, whereby to release said device for withdrawal amsaid pipe string. 2. An anchoring device according to claim 1 wherein (Istop means comprises an annular groove in the exior of said mandreldefining longitudinally spaced )ulders, and a stop member mounted on thebody to )jfiCt into said groove for alternate engagement with dshoulders. 5. An anchoring device according to claim 2 wherein d stopmember comprises a segmented ring resiliently sed to radially collapseinto said groove between said uulders. 1. An anchoring device accordingto claim 1 wherein 1 releasable latch elements comprise an annulargroove the exterior of said mandrel, and ball detents mounted the bodyand resiliently biased to enter said groove en in registrationtherewith. 5. An anchoring device according to claiml having seal ansmounted about the exterior of said body to seal ween the body and thewall of the pipe string, and co- :rating passages in the mandrel andbody arranged to by- :s fluid around said seal means. i. For use in pipestrings having longitudinally spaced iular recesses in the wall thereof,an anchoring device :horable in a selected one of said recesses,comprising, ibular body insertable in the bore of a pipe string, opensin the wall of said body, latch members mounted in 1 openings for radialmovement into and out of said esses, said latch members having inwardlyprojecting ulder means, a mandrel disposed in the bore of said ly forlongitudinal movement relative thereto, the upper l portion of themandrel extending above the upper l of the body and having a closuremember closing off bore of the mandrel, radial enlargements on the ndrelmovable with the mandrel relative to the latch mbers between positionsin and out of registration with l shoulder means, whereby respectivelyto radially ject said latch members into said recesses and to release Ilatch members for retraction from said recesses, crating stop meanscarried by the body and the mandrel iting the relative movement of themandrel to attainit of said positions, cooperating releasable latcheleits positioned on the body and mandrel to releasably ire said mandrelto the body when said shoulder means n registration with the shouldermeans on said latch nbers, and sleeve means slidably disposed about saider portion of the mandrel and engageable therewith applying upward pullon said mandrel to release said h elements and to move said enlargementsout of stration with the shoulder means on said latch meml, whereby torelease said device for withdrawal from i pipe string. An anchoringdevice according to claim 6, wherein l upper portion of said mandrel hasport means through wall thereof, and said sleeve means carries valve insmovable between positions opening and closing l port means. An anchoringdevice according to claim 6, wherein 1 stop means comprises an annulargroove in the ex- )r of said mandrel defining longitudinally spacedulders, and a stop member mounted on the body to project into saidgroove for alternate engagement with said shoulders.

9. An anchoring device according to claim 6, wherein said releasablelatch elements comprise an annular groove in the exterior of saidmandrel, and ball detents mounted in the body and resiiiently biased toenter said groove when in registration therewith.

10. An anchoring device according to claim 6, having seal means mountedabout the exterior of said body to seal between said body and the wallof the pipe string, and cooperating passages in the mandrel and bodyarranged to by-pass fluid around said seal means.

11. For use in pipe strings having longitudinally spaced annularrecesses in the wall thereof, an anchoring device anchorable in aselected one of said recesses, comprising, a tubular body insertable inthe bore of a pipe string, openings in the wall of said body, latchmembers mounted in said openings for radial movement into and out ofsaid recesses, said latch members having inwardly projecting shouldermeans, a tubular mandrel disposed in the bore of said body forlongitudinal movement relative thereto and defining an annular chamberbetween the mandrel and the body closed at its opposite ends, radialenlargements on the mandrel movable with the mandrel relative to thelatch members between positions in and out of registration with saidshoulder means, whereby respectively to radially project said latchmembers into said recesses and to release said latch members forretraction from said recesses, cooperating stop means carried by thebody and the mandrel limiting the relative movement of the mandrel toattainment of said positions, cooperating releasable latch elementsincluding detent means positioned in said chamber and a detentreceivinggroove positioned on the mandrel to releasably secure said mandrel tothe body when said shoulder means is in registration with the shouldermeans on said latch members, port means through the wall of the mandrelproviding communication between the bore of the mandrel and the interiorof said chamber below said detent means, and means for applying upwardpull on said mandrel to release said latch elements and to move saidenlargements out of registration with the shoulder means on said latchmembers, whereby to release said device for withdrawal from said pipestring.

12. An anchoring device according to claim 11, wherein said detent meanscomprises a plurality of annularly arranged ball elements, a pistonmember slidably disposed in said chamber beneath said ball elements, andspring means resiliently urging said piston member into engagement withsaid ball elements to urge the latter outwardly toward saiddetent-receiving groove.

13. An anchoring device according to claim 11, wherein the area of themandrel and the area in said chamber exposed to fluid pressure enteringthe chamber through said port means from the bore of the mandrel areequal whereby to balance the pressure across the mandrel.

References Cited in the file of this patent UNITED STATES PATENTS2,953,206 Brown Sept. 20, 1960 2,976,931 Daf'lin Mar. 28, 1961 2,980,185Daffin Apr. 18, 1961

1. FOR USE IN PIPE STRINGS HAVING LONGITUDINALLY SPACED ANNULAR RECESSESIN THE WALL THEREOF, AN ANCHORING DEVICE ANCHORABLE IN A SELECTED ONE OFSAID RECESSES, COMPRISING, A TUBULAR BODY INSERTABLE IN THE BORE OF APIPE STRING, OPENINGS IN THE WALL OF SAID BODY, LATCH MEMBERS MOUNTED INSAID OPENINGS FOR RADIAL MOVEMENT INTO AND OUT OF SAID RECESSES, SAIDLATCH MEMBERS HAVING INWARDLY PROJECTING SHOULDER MEANS, A MANDRELDISPOSED IN THE BORE OF SAID BODY FOR LONGITUDINAL MOVEMENT RELATIVETHERETO, RADIAL ENLARGEMENTS ON THE MANDREL MOVABLE WITH THE MANDRELRELATIVE TO THE LATCH MEMBERS BETWEEN POSITIONS IN AND OUT OFREGISTRATION WITH SAID SHOULDER MEANS, WHEREBY RESPECTIVELY TO RADIALLYPROJECT SAID LATCH MEMBERS INTO SAID RECESSES AND TO RELEASE SAID LATCHMEMBERS FOR RETRACTION FROM SAID RECESSES, COOPERATING STOP MEANSCARRIED BY THE BODY AND THE MANDREL LIMITING THE RELATIVE MOVEMENT OFTHE MANDREL TO ATTAINMENT OF SAID POSITIONS, COOPERATING RELEASABLELATCH ELEMENTS POSITIONED ON THE BODY AND MANDREL TO RELEASABLY SECURESAID MANDREL TO THE BODY WHEN SAID SHOULDER MEANS IS IN REGISTRATIONWITH THE SHOULDER MEANS ON SAID LATCH MEMBERS, AND MEANS FOR APPLYINGUPWARD PULL ON SAID MANDREL TO RELEASE SAID LATCH ELEMENTS AND TO MOVESAID ENLARGEMENTS OUT OF REGISTRATION WITH THE SHOULDER MEANS ON SAIDLATCH MEMBERS, WHEREBY TO RELEASE SAID DEVICE FOR WITHDRAWAL FROM SAIDPIPE STRING.